Development Of The Genital System - 2/19 Cole Flashcards
When does phenotypic sexual differentiation begin?
Complete?
Week 7
Week 20
What do primordial germ cells originate from?
Endoderm of yolk sac
What guides the migration that is expressed on PGCs?
Failure of PGCs to reach the genital ridge leads to what?
C-kit receptor and stem-cell factor (c-kit ligand)
Gonadal dysgenesis
What do Sertoli cells secrete?
What does this do?
MIS/MIF/Anti-mullerian hormone
Regression of Paramesonephric (Mullerian) Ducts
Where are leydig cells located?
What do they secrete?
Interstitial cells
Testosterone
What is critically important to ensure the formation of Sertoli cell formation and differentiation?
SOX9 and SF1
What is characterized by short limbed dwarfism, bowing of long bones and skeletal features like hypoplastic lungs, malformations of cervical spine, heart and kidneys?
Due to what?
Campomelic dysplasia
SOX9
What is DHT mainly responsible for in males?
Masculinization of external genitalia and prostate
What does testosterone do after released from leydig cells?
Masculinization of reproductive system (Wolfian duct)
Which kind of 5a-reductase is made by reproductive tract?
Where?
Type II
Epididymis, seminal vesicle, prostate
When do the primary (medullary) cords degenerate by in females?
10th week
In females the mesonephric ducts degenerate except for what?
Where are they found?
Epoophron and paroophoron
Mesentery of ovary
What are portions of the mesonephric duct left in the female called?
Gartner’s duct
What up regulates DAX1 in the female?
What does DAX1 do?
WTN4
Blocks SOX9 and AMH
When do the Paramesonephric (Mullerian) ducts develop?
Where?
6th week
Lateral to mesonephros
The paired portions of the Paramesonephric ducts become what?
Uterine tubes
What does the uterovaginal primordium become?
Epithelium and glands of the uterus, epithelium of upper 1/3 of vagina, muscular wall of vagina
EEM
Where does the inferior portion of the vagina form from?
Tissue from where?
Posterior wall of Urogenital sinus
Sinovaginal bulbs
When can a 46 XY male have persistent Paramesonephric ducts?
Low AMH or abnormal response to AMH
What is MRKH?
Failure of the Paramesonephric ducts to develop
Missing uterine tubes, uterus and variable malformation of the upper portion of the vagina
Imperforate hymen can cause what?
Primary amenorrhea (absence of menses)
Hematosalpinx -> endometriosis and adhesion formation
Hemoperitoneum
What does the genital tubercle form in the male?
Urethral folds?
Labioscrotal swellings?
Phallus
Penile urethra
Scrotum
In the female, what does the genital tubercle become?
Urethral folds?
Labioscrotal swellings?
Clitoris
Labia minora
Labia majora
What is cryptorchidism?
Undescended testes
Usually descend in 1st year, associated with increased testicular cancer
What is hypospadias?
What causes it?
Urethra opens onto the ventral aspect of penis
Inadequate androgens or inadequate receptor sites for DHT
What is epispadias?
What does it occur with?
Urethral meatus opens on dorsal side of penis
Bladder exstrophy
Genotype of Klinefelter syndrome?
Characteristics?
47 XXY
Small testes, low levels of testosterone, elongate limbs, poor development of secondary sexual characteristics
Genotype of Turner’s syndrome?
Characteristics?
45X or Mosiac 46XX
Short, no adolescent growth, broad chest, CHD
Secondary sex characteristics do not develop
What is pseudo intersexuality?
Genotype?
External genitalia of one sex accompanies gonads of the other sex
46XX or 46XY
What can cause 46XX DSD?
Exposure after 12th week leads to what?
Prenatal exposure to androgens
Clitoris hypertrophy
Genotype of AIS?
Cause?
Characteristics?
46 XY DSD
X-linked disorder where receptors unresponsive to androgens
External genitalia are feminine, undescended testes
5a-reducatase deficiency (5-ARD) is failure of what?
Result?
Genotype
Inability to convert testosterone to DHT
Born with ambiguous genitalia, normal mesonephric duct derivatives, “first women, then man)
46XY DSD
When can M/F external genitalia be recognized?
Week 12
